Skip fuse for antitank mines



Oct. 21, 1947. I TRAYLOR 2,429,246

SKIP FUSE FOR ANTITANK MINES Filed D90. 15, 1943 Fig-1" 4 45 1 /6 I6 9 la [a 2 4/ 2 I I 2 1 6 1 93":

J0 H N ELTRAYLEIR Patented Oct. 21, 1947 U TN'TT ED STATES or F 1c (Granted; under 431161316;

amended=April*30, 1928;2;370;0. G. 7579 The invention: -described,herein may-be manus z factured-and used by or for the Government-for governmental j-purposes, without, the payment to me of any royalty thereonira The present invention relates toa contact mine 5 and rnonesparticularly to a skiprfuse or explodern; therefore It is constructed throughoutof mates, rial, non-responsive to magnetic-influence and; thereiora its presence cannot be detected by mag-; neticiinstruments usually employed: formine die-(H110 tection; n

The tusesor exploder for exploding the main 1 charge i-s-'-regulable in advance topredetermine the: r, numbergof impacts on inefiectiveoperations-the mine canendure :prior to the operationathat ex-- plodes it. It operates somewhat upon thebellowsm. principle; with means for reestablishing. the normal,.1:e1ative.positions of the main; body parts,;-;;- after each impact or Contact; short of the;1ast*0r i, efiectiveionel 1 Among the outstanding features of novelty, so, faras I- am=-now:advised-,- is the firing device comparable in functionto that ,elementin fuses-des-. ignated as the-:fi-ring pin, This is madein aplu 1 ralityoi components iineffectively arrangedin the, firstinstance, that is tosay, that the preanrangee, ment of the components orincrements ,issuch-that'tthenmulti-partEfiringe-devicewill not; be -long---, enoughto contribute its partin the explosion of thamineruntil after the mine hasbeen impacted -3 or contacted a predetermined numberof times. '1'

Thegeneral obj ectoithe invention-is to produce a mine that willlbe reliable, in operation, safeto handle, and, as. intimated, one that cannot be 10- a catedby magnetic instruments usually" employed for detecting the presence of mines;

It islto be understood that the word operation- -xr usedthroughout the following specification and in. a the claims .is intended to describe'the movements. of thelmine sections to and from eachother. pree liminary to the :last or explodingoperation, during whichzpreliminary operations certain parts of v the :mine are being conditioned for the final or exploding :operation.

In the drawings:

Figure l is a central vertical section of the mine, the parts being in normal position, there being shown in dotted lines positions of a number of components of the firing device, the dotted components with the lowermost one in full lines, showingthe line-up for the effectiveoperation of thevmine.

Figure 2 is. albottomiplan View of theholderwfor the components pt the-firing device Figured)? viswas section? of the holder. on the. line 3-3 of; Figural-1:1

Figure 14. is 560131011: of, themolder on .the lines-.- 4@ of Figure: 2:,

s The numeral -l designates the :main :bOdYnQf theniine which comprises; an inverted'cupqshapedtw section-2i having a chamber for thetmaimexplfla siverchar-ge 4;,a-nda lower! dish-shaped *section -5,- having-apentral depressions-tor sump, 5:, the sec- ,tions being preferably of porpelaineor, somegotherw substantialthen-magnetic materia-L eilhe bottom of thezuppersection is=cl0sedsby a laminatedid-isk 6, otca-rdboard or-l-i-ke material of sufiicient stame-w inasta properly-e confine vt1-1eexp.losive charge. and;m to stand-the-pressure incident .to depressing the; upper section -toward.the lowers oneyagainsttthel s means for ,returning ,saidrupper; sectiontto non-w} malr position afterbeing depressed-in. some open-s, atiomofrthemine short-.otthe,final onen.

h The dish d-has 1a .-centr.aL-opening It which :re-. ceiveslthe-Jowenendmf a cylinder} extending upwardly :to a point,near.thehundersidesof the; cuprshaped':sectiontL-the cylinder being: of plasma, tic materialtor other nonmagnetic-material of sufiicientqintegrityto cooperate in sustaining ,its partotthe,strainsimposed upon .theminein the various :stagesotits contemplateduse Theuppernsectionlis provided with an inter-W nallyathreaded central opening, 9,. partially closed t by -a,threaded plug-,JU formed with-ajiangell a engaging an annular shoulderfllfi in. atdepression in thewtoppoi saidisectionu'gThe .tplugalfi is internallynthreadedr .to receive, the... externally, threaded .c1osure plug .l3 whiehlhassa. reduced threaded portion 9.1.4 received in thezthreadedup-n per end of a cylindrical fuse housingwl5, ,the Q 7 threads ,in the, housingaextendinglbelowijthose necessaryviorithe(attachment. of. the, closure .plug; l fol; a purpose that will,ipresentlysa pear. plug it, like the-plug ill, ispnoyided withja flange. l 6 whichibears .upon a compressible disk 16 in-.. terposedbetweenstheflangemandntheftop of the pluglfl.

'Iheiusewhousing is, H.-shaped.in section, .thus proyidingafioorror partitionl] which is pro,-. vided with 1a,.fiash passage. ll 8 therethroughv com- 4 municating at its upper end with a chamberlfi formedby thewallsofthe housing and a.remov-. ablethreadedldiskjlfl, .the; threads of which disk occupy thefextendedthreads of the fuse housing.

Thejlowerpartof the housing below the floorv I1 is internallyandrsomewhat, extensively thread-,1 ed as shown, ,theithreadsextending short "of the", floor. The lowenpart-of the,housing.is occupied uppermostlyby athreadedthimblell having-a central shouldered aperture, near its lower end, the bottom of the thimble being cone-shaped. Below the thimble the housing receives the threaded head 22 of the firing device holder 23. This holder has a central bore 24 opening at its upper end into a shallow cone-shaped chamber 25. The lower end of the holder has a flange 26 which forms a seat for the lowermost element 21 of the multi-part firing pin, which component is the one to whose length is added other components, in this case a plurality of balls 21, preferably of glass or agate. A lateral integral extension 28 open at its upper end communicates at its lower end with the holder and forms a pocket for the balls 21'. The wall of the holder is recessed as indicated at 30 for the passage of a spring finger 30' whose lower end extends through the recess into the bore of the holder, the finger serving to hold the ball in the bore of the holder after it has been forced from the bottom thereof by the element 21. The space below the lower end of the finger and the bottom of the pocket is such as to permit the passage of a ball past the end of the finger out on to the top of '21 in position to be forced upwardly upon the upward movement of said element 21, when movement is effected by the contact of said element with the bottom of the sump in the porcelain section 5, as will more fully appear in the description of the operation.

Below the closure plug I3 in the fuse housing is the threaded removable disk 20 which holds in position a disk 33 of suitable primer material, which in turn rests upon an annular booster pellet 34 seated on the floor I! of the housing. In the center of the pellet is a detonator 35 communicating with a primer charge 36 contained in an opening in the top of the thimble 2|. A transverse bore in the thimble receives a capsule 36", stabilized in the bore by a suitable cement. The capsule is in position to be crushed upon operation of the firing element 37, whose head is supported in the shouldered aperture in the thimble. The lower portion of this firing element extends slightly into the open upper end of the bore of the holder in position to be engaged by the uppermost ball or component of the firing device in that operation of .the mine that is to be the effective one. A spring washer 38 engaging a groove in the piston body, holds the piston head seated in its aperture in the thimble.

Surrounding the cylinder 8 is an annular receptacle 39, open at its upper end and receives an additional booster charge of suitable explosive material adapted to be set off by the charge in the fuse holder.

As stated at the outset the mine operates upon the bellows principle, in that the upper and lower sections are moved in relation to each other, and means is required to restore the sections to normal position in an operation short of the one in which the mine is exploded. For this purpose, there is interposed between the laminated disk '6 and the lower section 3, a ring 40 of sponge rubber or other resilient material which may be replaced by a spring made of some non-magnetic material.

The 'upper and lower sections are suitably spaced apart and are virtually entirely surrounded by a suitable number of layers of canvas 4! or other suitable flexible non-magnetic material that will allow the sections to be moved toward each other, or in the manner of intended operation, the top section moved toward the lower one, responsive to a pressure upon the top of the mine 4 such as that produced by the weight of a vehicle, and to limit their movement in the opposite direction, in operations short of the final one.

Space is left between the cylinder 8 and the fuse housing so that the fuse unit may be readily inserted in the mine, and to make the plugs 10 and I 3'conveniently available the canvas stops considerably short of the center of the top of the upper section, and its inner boundary is preferably defined by a ring 42 seated on the top section. .Within the ring is a rubber ring 43, the interior of which is occupied by the upper plug l3, with no part of the plug extending above the ring.

vThe main charge may be of any suitable explosive, and also the primer materials. The booster pellet and detonator 35 may employ conventional ingredients; the contents of the capsule may be an acid component and the primer material associated closely therewith may be a compound ignited by contact with sulphuric acid as is well known in the art, and obviously the multipart firing device shown may be employed to actuate any suitable primer for initiating explosions or for starting powder trains etc.

An appropriate number of firing device components, balls in the present embodiment of the invention, are placed in the pocket in the extension 28, the number determining the number of inefiective operations the mine will endure before the final or exploding one. The lowermost ball, by gravity, rolls out upon the firing element 21, there to stay until the upper section of the mine is depressed, when the element 21 striking the bottom of the sump 5' will force it upwardly above the spring finger 30. Obviously, in succeeding operations like that just explained, the balls will be built up in the bore 24 until they span the distance between the lower and upper firing elements 21 and 31, when upon the succeeding operation of the mine, it will be exploded.

As stated, the mine is made of non-magnetic material throughout and will, preferably, where feasible be made of plastic. However, the upper and lower sections will preferably be made of porcelain or like material with insulating properties and offering such resistance to the explosion as to fragment destructively. The components of the firing device will preferably be of glass or agate and of such weight and smoothness as to assure that they fall quickly, by gravity, to position to be fed into operative position. 7

The mine illustrated is arranged to be exploded on the fourth impact, there being four balls in the holder. Should it be desired to have it explode On some other impact within the range of the number of balls in the holder, the fuse housing will be removed and the element 21 manually manipulated to feed a number of balls into alignment with the elements 21 and 31. In order that one may see the number of balls so fed, I provide a narrow elongated slot 44 in the holder. Ordinarily this manual manipulation will not be neces sary, since the order of explosion will be taken care of in the first place, but in some emergency or in the force of changed plans, such variation in the exploding order might be desirable.

I claim:

1. A contact mine comprising a pair of relatively movable spaced sections, one of which contains an explosive charge, resilient means normally holding said sections in spaced relation, a. fuse carried by one of the sections and including a primer and a firing element, a firing device carried by one of the sections and comprising a plurality of separate components, a predetermined number of which are adapted to be successively brought into alignment with said firing element until said components span the space between extension, an 'upper firing'element in the fuse adjacent the primer charge, and a second firing element reciprocable in the lower end of said hollow extension, said lower element arranged to be reciprocated by contact with the lower section, and an additional firing device comprising separate components between the upper and lower firing elements but normally out of line therewith, said additional components being adapted to be fed by the lower firing element successively into alignment with said upper firing element upon the reciprocation of the lower element until the additional components span the space between the last fed components and the upper firing element to complete the firing means.

3. A contact mine comprising upper and loWer relatively movable sections, the upper section adapted to receive the main explosive charge, resilient means spacing said sections apart and for returning the upper section to normal position, a removable plug in the top of the upper section, a fuse housing carried by said plug and extending in proximity to said charge, said housing formed with a transverse partition intermediate its ends and having a flash passage therethrough, a booster charge and a primer charge seated on the upper side of said partition, a thimble below the partition and having an axial opening therethrough communicating with the flash passage, a firing element in the lower part of the opening and a priming charge in the upper part, said thirnble being further provided with a transverse bore having therein a capsule of frangible material and containing a primer igniting fluid, said capsule being adapted to be ruptured by the firing element, a hollow extension carried by said housing and having a pocket at one side thereof opening into the lower part of said extension, a second firing element reciprocable in the lower part of the extension, and a predetermined plurality of balls in the pocket arranged to be fed consecutively toward the upper firing element by a succession of contacts between the lower firing element and the lower mine section until the space between the upper and lower firing elements is spanned by said balls whereby to explode the mine upon its succeeding operation.

4. The invention of claim 3, characterized in that the hollow extension of the fuse housing has a spring finger extending into the path of movement of the firing device components to support the components when they have been fed beyond the end of the finger.

5. The invention of claim 3, characterized in that the upper and lower sections have suitably secured thereto a covering of flexible material securing the internal parts of the mine in proper relative position and permitting the bellows-like action of the mine in operation.

6. A contact mine comprising a pair of spaced sections, means connecting said sections for movement toward and from each other, resilient means urging said sections into spaced relation, a fuse carried by one said section and including a primer and a firing element, a plurality of separate components mounted in a channel between said sections, and means between said sec tions including a pin spaced from said firing element and movable by and in response to relative movement of said elements, to successively feed said components into the space between said firing element and pin whereby to fill said space and mechanically transmit to said firing element a final one only of a predetermined number of movements of said pin.

7. In an explosive contact mine, a pair of sections, means connecting said sections for guided movement toward and from each other, resilient means urging said sections into spaced relation, detonator means in one element and including a firing element, a firing pin spaced from said element and movable in response to relative movement of said sections, a plurality of balls,

and means for feeding said balls individually into the space between said pin and element by and in response to relative movement of said elements to fill said space and thereby mechanically connect said pin and element and detonate the mine only after a predetermined number of relative movements of said sections.

8. A contact mine comprising a pair of relatively movable sections, a normally spaced detonator and firing pin in said mine, a series of balls in said mine, and means responsive to relative movements of said sections to feed said balls into the space between said detonator and firing pin to thereby mechanically connect said pin with said detonator after a predetermined number only of said movements.

JOHN B. TRAYLOR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,228,905 Bold Jan. 14, 1941 2,368,310 Lecky et al Jan. 30, 1945 FOREIGN PATENTS Number Country Date 541,624 Great Britain Dec. 4, 1941 

